Method of forming rivets



(No Model.)

I. G. PLATT.

METHOD OF FORMING RIVETS.

No. 449,699. Patented Apr. 7, 1891.

WITNESSES: llVl/E/VTOI? @M' Mw ATTORNEY.

UNITED STATES PATENT IRVING G. 'PLAT'I, OF \VATERBURY, CONNECTICUT.

-METHOD OF FORMING RIVETS.

SPECIFICATION forming part of Letters Patent No. 449,699, dated April 7, 1891.

Application filed April 19, 1890. Renewed February 2, 1891. $erial No. 379,917. (No model.)

Be it known that I, IRVING G. PLATT, a citizen of the United States, and a resident of \Vaterbury, in the county of New Haven and State of Connecticut, have invented certain new and useful Methods of Forming Rivets, of which the following is a specification.

My invention relates to an improved process or method of forming slotted rivets, and more particularly to that kind or class thereof which are formed from a piece of wire and adapted to cut or pierce their own way through the fabric or other article to which they are attached.

Heretofore in constructing rivets from wire or like material it has been the practice to remove so much of the metal from the center as will sulficiently sharpen or thin the ends of the prongs to enable the latter to pierce their way through the material to which they are applied, or to first remove the greaterportion of the metal from the center of the shank of the rivet and subsequently chisel the'ends of the prongs on the outer side; but such end is accomplished at the expense of the holdingsurfaces of the prongs, as it is obvious that the greater the amount of metal removed from the center toward the outer surfaces of the prongs the less holding-surface there will be, which is of course due to the cylindrical shape of the metal from which the prong is constructed. I

The object of my invention is to form the rivet in such a way that the central portion of the rivet, which is necessarily greatest in width, will be utilized as the holding-surfaces of the shank; and with such end in view my method consists,substantially,in first striking up or otherwise forming the head or flange upon one end of the shank, in slitting or slotting the shank of the rivet, then spreading the prongs apart, and finally swaging or cutting away the outer surface of the prongs.

To more fully explain my improved method of forming rivets, reference is had to the accompanying drawings, in whicl Figure 1 is a view in elevation of the rivet after the head has been formed thereon and the shank slitted or slotted. Fig. 2 is a plan view thereof. Fig. 3 is a View showing the rivet in its second stage, the prongs having been spread apart. Fig. 4 is aplan view thereof.

Fig. 5 is a View in elevation of the finished rivet, the outer surfaces having been swaged or cut away afterthe prongs have been spread apart, as shown in Fig. 3; and Fig. 6 is a plan view of the finished rivet as shown in elevation in Fig. 5.

A represents the head of the rivet, formed of wire or similar material, and B the shank thereof, provided at its center with a slit or slot a, in forming which latter the least amount possible of metal is removed, the object being to retain to the greatest extent the metal occupying the center of the shank, in order to utilize as holding-surfaces the greatest width of metal. After the shank has been provided with said slits or slots a the prongs Z) I) are separated or spread apart by suitable meansas, for instance, by a tool of wedge shape, (not shown,) the rivet assuming the shape as shown in Fig. 3 of the drawings. The outer surfaces of these prongs are then cut away, the effect of which is to form each prong of wedge shape, at the same time retaining or utilizing the central portion of the rivet and forming the piercing ends of a width equal or nearly equal to thediameter of the shank before being slotted. Instead of cutting away the outer surfaces of these prongs, as above described, the same end may be accomplished by removing a somewhat greater amount of metal from the center of the rivet, and subsequently swaging the prongs to such an extent that they will be the same or substantially the same in width as in the case of removing the minimum amount of metal from the center and subsequently cutting away the outer surfaces, the flattening or spreading of the metal by the process of swaging compensating for the extra amount of metal removed from the center.

In swaging or removing the outer portions of the shanks, as above described, I prefer to form them concave in shape, in order to secure an extra thickness of metal on the vertieal edges of the shanks and the resulting increase in strength.

It will of.eourse be understood that I do not limit my claim to the steps in the succession as I have above described, as it may at times be desirable to remove the outer surfaces of the prongs before spreading them apart; or, again, it may benecessaryor found desirable to remove this outer surface before I forming slotted rivets, which consistsin formthe shank is slitted or slotted, and this withing the flange or head upon one end of the 15 out in any way affecting the result or the shank, slitting or slotting the latter, spreadspirit of my invention; but ing the prongs apart, and so removing the 5 IVhat I claim as new, and desire to secure outer surfaces of said prongs as to form them by Letters Patent, isconcave in shape.

1. The method or process hereinbefore 'de- Signed at New York, in the county of New 20 scribed of forming slotted rivets, which con- York and State of New York, this 17th (layof sists in forming the flange or head upon one April, A. D. 1890.

[0 end of the shank, slitting or slotting the I IRVING G. PLATT.

shank, separating the prongs, and removing \Vitncsses: the outer surfaces of the latter. HERMAN GU STOW,

2. The method hereinbefore described of l GEORGE COOK. 

